1. Field of the Invention
The present invention generally relates to a communication system and, in particular, to a real-time charging system and method for a communication system that is capable of managing the charging information related to the services provided to a user terminal and updating a QoS and charging rule efficiently in real time.
2. Description of the Related Art
FIG. 1 is a schematic diagram illustrating a conventional real-time charging system. As shown in FIG. 1, the conventional real-time charging system includes a packet processing node (Policy and Charging Enforcement Function) 100, a QoS and charging rule management server (Policy and Charging Rule Management) 200, and a real-time charging function server (Real Time Charging Function) 300 deployed in a network 20.
The packet processing node 100 interoperates with the QoS and charging rule management server 200 and receives QoS and a Policy and Charging Control Rule from the QoS and charging rule management server 200. The packet processing node 100 requests the Real-time charging function server 300 for a real-time charging amount according to the QoS and Policy and Charging Control Rule.
FIG. 2 is a diagram illustrating how to deliver a charging rule in the conventional real-time charging system.
As shown in FIG. 2, a user terminal 10 can be connected to a plurality of packet processing node 100 (100a, 100b, . . . , 100n) and serviced by individual packet processing nodes 100. Each packet processing node requests the QoS and charging rule management server 200 to send a QoS and a charging rule for providing a packet service. The QoS and charging rule management server 200 sends the QoS and charging rule defined per user terminal to the packet processing node 100. Upon receipt of the QoS and charging rule, the packet processing node 100 requests the real-time charging function server 300 for quotas fulfilling the QoS and charging rule. The Real-time charging function server 300 checks the QoS and charging rule and allocates the quota fulfilling the QoS and charging rule to the packet processing node 100.
However, when the QoS and charging rule is changed in the middle of the real-time charging service, there is no function to inform the change of QoS and charging rule from the real-time charging function server 300 to the QoS and charging rule management server 200 and/or the packet processing node 100 in the conventional wireless communication system. Conventionally, the Real-time charging function server 300 informs the packet processing node 100 of the change in QoS and charging rule and then the packet processing node reports the change to the QoS and charging rule management server 200, but this method increases the traffic overload. Also, this conventional method has another drawback in that the QoS and charging rule cannot be changed before the packet processing node 100 re-requests the real-time charging function server 300 for quota allocation when it is running out of quotas allocated to the user terminal 10.